scholarly journals A Near-Infrared Trace CO2 Detection System Based on an 1,580 nm Tunable Diode Laser Using a Cascaded Integrator Comb (CIC) Filter-Assisted Wavelength Modulation Technique and a Digital Lock-in Amplifier

2019 ◽  
Vol 7 ◽  
Author(s):  
Guolin Li ◽  
Enting Dong ◽  
Wen-hai Ji
Keyword(s):  
Diode Laser ◽  
Near Infrared ◽  
Detection System ◽  
Tunable Diode Laser ◽  
Wavelength Modulation ◽  
Modulation Technique ◽  
Co2 Detection ◽  
Cic Filter ◽  
Lock In

A high-sensitivity, near-infrared tunable-diode-laser-based photoacoustic water-vapour-detection system for automated operation

1999 ◽  
Vol 10 (11) ◽  
pp. 999-1003 ◽  
Author(s):  
Zoltán Bozóki ◽  
János Sneider ◽  
Zoltán Gingl ◽  
Árpád Mohácsi ◽  
Miklós Szakáll ◽  
...  
Keyword(s):  
Diode Laser ◽  
Water Vapour ◽  
Near Infrared ◽  
Detection System ◽  
High Sensitivity ◽  
Tunable Diode Laser

A near-infrared acetylene detection system based on a 1.534 μm tunable diode laser and a miniature gas chamber

2016 ◽  
Vol 75 ◽  
pp. 93-99 ◽  
Author(s):  
Qixin He ◽  
Chuantao Zheng ◽  
Huifang Liu ◽  
Bin Li ◽  
Yiding Wang ◽  
...  
Keyword(s):  
Diode Laser ◽  
Near Infrared ◽  
Detection System ◽  
Tunable Diode Laser ◽  
Gas Chamber

In-situ CO measurement of gas and oil combustion flame using near infrared tunable diode laser with direct and modulated absorption signals

2013 ◽  
Vol 306 ◽  
pp. 99-105 ◽  
Author(s):  
Qun-xing Huang ◽  
Fei Wang ◽  
Hai-dan Zhang ◽  
Jian-hua Yan ◽  
Ming-jiang Ni ◽  
...  
Keyword(s):  
Diode Laser ◽  
Near Infrared ◽  
Tunable Diode Laser ◽  
Combustion Flame

scholarly journals Near-Infrared C2H2 Detection System Based on Single Optical Path Time Division Multiplexing Differential Modulation Technique and Multi-Reflection Chamber

2019 ◽  
Vol 9 (13) ◽  
pp. 2637 ◽  
Author(s):  
Biao Wang ◽  
Hongfei Lu ◽  
Chen Chen ◽  
Lei Chen ◽  
Houquan Lian ◽  
...  
Keyword(s):  
Near Infrared ◽  
Detection System ◽  
Optical Path ◽  
Integration Time ◽  
Allan Deviation ◽  
Differential Modulation ◽  
Time Division Multiplexing ◽  
Detection Range ◽  
Modulation Technique ◽  
Time Division

A time division multiplexing differential modulation technique is proposed to address the interference problem caused by the fluctuation of laser light intensity in the single optical path detection system. Simultaneously, a multi-reflection chamber is designed and manufactured to further improve the system’s precision with an optical path length of 80 m. A near-infrared C2H2 detection system was developed. The absorption peak of the acetylene (C2H2) molecule near 1520 nm was selected as the absorption line. A laser driver is developed, and a lock-in amplifier is used to extract the second harmonic (2f) signal. A good linear relationship existed between C2H2 concentration and the 2f signal, and the correlation coefficient was 0.9997. In the detection range of 10–100 ppmv, the minimum detection limit was 0.3 ppmv, and the precision was 2%. At 50 ppmv, C2H2 and continuous detection for 10 h, the data average was 50.03 ppmv, and the fluctuation was less than ±1.2%. The Allan variance method was adopted to evaluate the long-term characteristic of the system. At 1 s of integration time, the Allan deviation was 0.3 ppmv. When the integration time reached 362 s, the Allan deviation was 0.0018 ppmv, which indicates the good stability of the detection system.

Optimization of Harmonic Detection System for Tunable Diode Laser Absorption Spectroscopy Based on Mathematical Algorithm

2018 ◽  
Vol 13 (10) ◽  
pp. 1533-1542 ◽  
Author(s):  
Danni Shen ◽  
Anji Yu
Keyword(s):  
Diode Laser ◽  
Absorption Spectroscopy ◽  
Detection System ◽  
Rapid Development ◽  
Noise Removal ◽  
Tunable Diode Laser ◽  
Gas Detection ◽  
Laser Absorption Spectroscopy ◽  
Laser Absorption ◽  
Diode Laser Absorption

Traditional gas detection technology has a certain degree of defects in all aspects, and it has not been able to adapt to the rapid development trend. Tunable diode laser absorption spectroscopy (TDLAS) technology has some good performance and is gradually being used in various industries. First, a gas detection instrument is designed. Then, based on subsequent data processing techniques, a wavelet transform algorithm is proposed, and the noise removal and baseline correction functions of the detection system are implemented. The results show that the proposed method has good removal effect on the inherent noise of the system and high efficiency. During the selection of the absorption line, the selected line of some gases cannot avoid the interference of adjacent peaks. Therefore, a mathematical analysis method of differential fold back algorithm is proposed. The absorption peak shape is squeezed by the method of adjacent phase subtraction and displacement superposition. The problem is solved well, and the accuracy of concentration measurement of some gases is effectively improved.

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